/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 *
 *  (C) 2003 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */
#include "mpi.h"
#include <stdio.h>
#include "mpitest.h"

int main( int argc, char **argv )
{
    int errs = 0;
    int rank, size, wrank, wsize, dest, a, b;
    MPI_Comm newcomm;
    MPI_Status status;

    MTest_Init( &argc, &argv );

    /* Can we run comm dup at all? */
    MPI_Comm_dup( MPI_COMM_WORLD, &newcomm );

    /* Check basic properties */
    MPI_Comm_size( MPI_COMM_WORLD, &wsize );
    MPI_Comm_rank( MPI_COMM_WORLD, &wrank );
    MPI_Comm_size( newcomm, &size );
    MPI_Comm_rank( newcomm, &rank );
    
    if (size != wsize || rank != wrank) {
	errs++;
	fprintf( stderr, "Size (%d) or rank (%d) wrong\n", size, rank );
	fflush( stderr );
    }

    /* Can we communicate with this new communicator? */
    dest = MPI_PROC_NULL;
    if (rank == 0) {
	dest = size - 1;
	a = rank;
	b = -1;
	MPI_Sendrecv( &a, 1, MPI_INT, dest, 0,
		      &b, 1, MPI_INT, dest, 0, newcomm, &status );
	if (b != dest) {
	    errs++;
	    fprintf( stderr, "Received %d expected %d on %d\n", b, dest, rank );
	    fflush( stderr );
	}
	if (status.MPI_SOURCE != dest) {
	    errs++;
	    fprintf( stderr, "Source not set correctly in status on %d\n", 
		     rank );
	    fflush( stderr );
	}
    }
    else if (rank == size-1) { 
	dest = 0;
	a = rank;
	b = -1;
	MPI_Sendrecv( &a, 1, MPI_INT, dest, 0,
		      &b, 1, MPI_INT, dest, 0, newcomm, &status );
	if (b != dest) {
	    errs++;
	    fprintf( stderr, "Received %d expected %d on %d\n", b, dest, rank );
	    fflush( stderr );
	}
	if (status.MPI_SOURCE != dest) {
	    errs++;
	    fprintf( stderr, "Source not set correctly in status on %d\n", 
		     rank );
	    fflush( stderr );
	}
    }

    MPI_Comm_free( &newcomm );

    MTest_Finalize( errs );

    MPI_Finalize();

    return 0;
}
